This invention relates in general to fluid dispensing apparatus, and more particularly to a method of and apparatus for lubricating an object by spraying the lubricant on the object.
The invention has been developed primarily though not exclusively as a means for efficiently and reliably carrying out in the field the lubrication of threaded connections of drill tubes used to bore long holes used in various operations ranging from oil and gas exploration to communication cable installation, lubrication of the threaded connections facilitating the end-to-end assembly of the drill tubes. Heretofore, lubrication of such connections has generally been carried out either manually or (frequently inadequately) with air-operated pumps. Manual lubrication requires the drilling operator to lose productive time by having to get out of his cab to apply the lubricant to the threaded connection by hand. Application by use of air-operated pumps to spray the lubricant on the threaded connections is generally ineffective to provide a good quality spray at temperatures ranging from +160xc2x0 F (+71xc2x0 C.) to xe2x88x9220xc2x0 F. (xe2x88x9229xc2x0 C.); at low temperatures air-operated pumps may even become inoperable. The invention has also taken into account the problem that certain zinc or copper-based greases specially formulated for lubricating drill tube connections are very difficult to pump and spray, and the further problem that prior methods of application have sometimes resulted in applying too much or too little lubricant to the connections.
Accordingly, among the several objects of the invention may be noted the provision of lubricant dispensing apparatus particularly for reliably and efficiently spraying lubricant on the threaded connections of drill tubes or open gears, even at low temperatures in the field, and enabling use of the aforesaid specially formulated lubricants; the provision of such apparatus which is readily adjustable to dispense or spray charges of lubricant of different selected volumes (ranging, for example, from 0.5 cubic inch to 2.00 cubic inches); the provision of such apparatus which obtains power for a spraying operation solely from pressure of lubricant supplied thereto; the provision of a method of spraying lubricant on a rotating object, including (but not limited to drill tube threads), with the duration of spray being synchronized with the rotation of the object to provide for a more accurate distribution of lubricant on the object; the provision of such a method which is applicable to spraying lubricant on the drill tube of a directional boring machine and other drilling/boring machines; and the provision of apparatus for carrying out the aforementioned method; and the provision of such method and apparatus in which the pattern, pressure, volume and duration of spray are controllable, as required by circumstances; and the provision of such apparatus which is readily mountable on a drilling/boring machine for applying lubricant to the threaded connections of the drill tube sections.
While the invention as it has been developed has been embodied in apparatus for spraying a charge of lubricant on a blast drill tube threaded connection, it is to be understood that the principles of the invention are also applicable to dispensing apparatus for fluids other than lubricants, for example sealants and adhesives, and to dispensing apparatus useful in packaging operations for dispensing measured or metered charges of fluid to packages. The term xe2x80x9cfluidxe2x80x9d as used herein is intended to cover principally any non-gaseous fluid, including viscous fluids such as greases.
In general, a method of the present invention involves the steps of spraying lubricant on a rotating object, and synchronizing the duration of spray to the rotation of the object so that the spray continues only for an interval of spray time corresponding to rotation of the object through a predetermined range of rotation.
Lubricant spray apparatus of the present invention can be used for spraying a rotating object with lubricant. The apparatus comprises a dispenser for spraying a volume of lubricant adapted for connection in a system for supplying lubricant under pressure to the dispenser for charging it with lubricant to be sprayed. The apparatus further comprises a delivery system for delivery of said volume of lubricant to be sprayed by the dispenser, including a discharge valve adapted to be closed for the charging of the dispenser and to be opened for spraying said volume; and a controller for controlling the timing of the opening and closing of the discharge valve so that the spray continues only for an interval of spray time corresponding to rotation of the object through a predetermined range of rotation.
In another aspect, this invention is directed to a directional boring machine for rotating a drill rod comprising a series of separate longitudinal sections having threaded ends for connection of the sections end-to-end. The boring machine comprises a chassis, a system for rotating the drill rod relative to the chassis, and dispensing apparatus mounted on the chassis for spraying lubricant on the threaded end of a drill rod section as it rotates.
In one embodiment, a lubrication system of this invention dispenses a lubricant to threads of a drill tube of a horizontal directional boring machine. The lubrication system comprises a pumping system comprising a lubricant reservoir, a pump, an applicator, and a lubricant supply conduit coupled between the pump and the applicator. A controller coupled to the pumping system is operable in response to an operator signal to activate the pumping system to dispense lubricant over a circumferential surface of the threads of the drill tube.
In a further aspect, a method of the present invention dispenses a lubricant on the threads of a drill tube held by a chuck of a horizontal directional boring machine. The method comprises rotating the chuck and/or drill tube, dispensing lubricant to the threads of the drill tube, and controlling the dispensing of lubricant to dispense lubricant over a circumferential surface of the threads of the drill tube.
In yet a further aspect, a lubrication system of the invention dispenses a lubricant to threads of a drill tube of a horizontal directional boring machine. The system comprises a pumping system comprising a lubricant reservoir, a pump, an applicator, and a lubricant supply conduit coupled between the pump and applicator. A heater is coupled to the pumping system, the heater heating lubricant within the pumping system. A controller is coupled to the pumping system. In response to an operator signal, the controller activates the pumping system to dispense a volume of lubricant from the applicator to the threads of the drill tube.
In another embodiment, a lubrication system of the invention comprises a body defining an expansible and contractible chamber, a pump for pumping lubricant to the chamber, a spray nozzle in communication with the chamber, and a device for contracting the chamber to force lubricant out of the chamber and through the spray nozzle at a pressure sufficient to effect spraying of the lubricant, without mixing the lubricant with air under pressure, on a part to be lubricated.
In still a further aspect, a directional boring machine of the present invention rotates a drill tube comprising a series of longitudinal sections having threaded ends for connection of the sections end-to-end. The boring machine comprises a chassis, a system for rotating a drill tube section, and dispensing apparatus mounted on the machine for spraying lubricant on the threaded end of the drill tube as it rotates. The dispensing apparatus comprises a body defining an expansible and contractible chamber, a pump for pumping lubricant to the chamber, a spray nozzle in communication with the chamber, and a device for contracting the chamber to force lubricant out of the chamber and through the spray nozzle at a pressure sufficient to effect spraying of the lubricant, without mixing the lubricant with air under pressure, on a part to be lubricated.
In another embodiment, a method of this invention involves spraying a part with lubricant. The method comprises pumping lubricant to an expansible and contractible chamber thereby to fill the chamber, and contracting the chamber to force lubricant out of the chamber and through a spray nozzle at a pressure sufficient to effect spraying of the lubricant on the part without mixing the lubricant with air under pressure.
Other objects and features will be in part apparent and in part pointed out hereinafter.